The catalytic oxidation of ether-alcohols according to the equation ##STR1## has been known for a considerable time and has been described, for example, in German Patent 2,936,123 and European Patent 206,054. With increasing molecular mass of the radical R, however, the separation and hence the complete recovery and recycling of the rare metal catalyst becomes more difficult.
It was therefore the object to develop a technically and economically acceptable process for separating catalysts from suspensions by filtration.